Corneal Sensitivity Changes and Nerve Plexus Abnormalities in Noninfectious Anterior Uveitis

Area of Science:

• Ophthalmology
• Neuroscience
• Corneal Science

Background:

• Anterior uveitis is a common intraocular inflammation.
• Corneal nerve alterations are increasingly recognized in ocular inflammatory diseases.
• The impact of unilateral noninfectious anterior uveitis on corneal nerves is not fully understood.

Purpose of the Study:

• To evaluate structural and functional changes in corneal nerves.
• To compare corneal nerves between affected, unaffected fellow eyes, and healthy controls.
• To investigate the relationship between inflammation and nerve alterations.

Main Methods:

• Cross-sectional study of 82 patients with unilateral noninfectious anterior uveitis and 25 healthy controls.
• Corneal sensitivity assessed using non-contact corneal aesthesiometer (NCCA) and Cochet-Bonnet aesthesiometer (CBA).
• In vivo confocal microscopy used to image corneal subbasal nerve plexus; nerve parameters quantified using ACCMetrics software. Inflammatory cells and microneuromas were counted.

Main Results:

• Affected eyes showed significantly higher NCCA thresholds (reduced sensitivity) and lower corneal nerve fiber layer (CNFL) length compared to controls.
• Affected eyes also had increased inflammatory cell density and microneuroma counts.
• Unaffected fellow eyes exhibited higher NCCA thresholds, reduced CNFL, corneal nerve fiber density (CNFD), corneal nerve fiber branching (CFracDim), and increased microneuroma counts compared to controls.

Conclusions:

• Unilateral noninfectious anterior uveitis leads to reduced corneal nerve sensitivity and structural nerve damage in the affected eye.
• Measurable corneal nerve alterations and reduced sensitivity are also present in the contralateral, clinically unaffected eye.
• These findings highlight the systemic impact of unilateral uveitis on corneal innervation.